The present invention relates generally to latching devices for compact devices with translating components and more particularly to latching devices for translating and rotating members on pocket-sized portable communication devices.
As a general rule, portable communication devices such as radiotelephones continue to shrink in size and to be configured in small compact packages (i.e., xe2x80x9cpocketxe2x80x9d sized radiotelephones). Recent radiotelephones have incorporated low profile designs. Low profile designs typically include a thin, light-weight cover member which xe2x80x9cflipsxe2x80x9d over the radiotelephone body when the radiotelephone is closed and xe2x80x9cflipsxe2x80x9d above and away from the radiotelephone body when the radiotelephone is opened. Consequently, this cover member is often called a xe2x80x9cflip.xe2x80x9d
The radiotelephone also typically includes an antenna element which, during operation, extends above the radiotelephone body. Radiotelephones have conventionally used various types of translating antennas, such as side-mounted swivel antennas and telescoping antennas. In a preferred low-profile application, the antenna is configured as a flexible xe2x80x9cbladexe2x80x9d or xe2x80x9cstripxe2x80x9d (i.e., a flexible strip transmission line) radiating element which can be very narrow, thin, and flexible. The blade antenna can rotate and extend similar to the flip described above. See, co-pending and co-assigned U.S. patent application Ser. Nos. 09/217,142 and 09/217,048. The contents of these applications are hereby incorporated by reference as if recited in full herein. In any event, the antenna and flip typically stow in a retracted position proximate to (close to, inside, or adjacent) the radiotelephone body when closed.
It is desirable to configure the radiotelephone to include a latching device which can secure the translating or rotatable member(s) against the main housing when stowed to minimize unplanned deployment. It is also desirable to include a latching device which can assure that the translating or rotating member remains in the open operational position during use.
Unfortunately, the size of the user""s pocket and/or a low profile radiotelephones can limit the space or area in which to fit a latching device. Indeed, many designs provide only a small volume for a latch mechanism. This small volume can reduce the robustness of a rotating but latchable hinge, especially when the latching hinge is positioned near the top of the radiotelephone. In a previous radiotelephone embodiment, a structural extended member has been configured to extend between the top and bottom of the radiotelephone to release the lock or latching mechanism to allow movement of the rotating member. However, on pocket sized radiotelephones, there is a limited amount of space available to position electrical or mechanical components (often less than 0.5 mm) around the boss of the housing to position such a flip release. Further, many flip models are relatively thin so it is undesirable to position the latching device on the flip itself. In addition, in operation, it is often ergonomically desirable to configure a latch mechanism to respond to a relatively small input force and position the latching device to be activated with easy operation (i.e., preferably single-handed engagement and disengagement).
It is therefore an object of the present invention to provide a latching mechanism which is robust, operationally easy to use, and which occupies a relatively small envelope.
It is another object of the present invention to provide a latching mechanism which can lock a rotatable member both in an open and closed position.
It is an additional object of the present invention to configure a latching mechanism such that it is operable with minimal force.
It is still another object of the present invention to provide a latching mechanism with an externally accessible lock release which can be automatically reset upon translation of the flip toward the closed position.
It is an additional object of the present invention to provide a latching mechanism for a linearly translatable antenna.
These and other objects of the present invention are provided by a latching mechanism with a cavity which includes a quantity of rheological fluid material in fluid communication therewith and a magnetic or electric field source operably associated with the rheological material. The cavity contains components (such as a rotational shaft, a linear damper, gear, clutch, or other mechanism) which translate and which contact the rheological fluid or material. The rheological material, in response to the application of the magnetic or electric field, frictionally adheres to the translating member to inhibit rotation or translation (i. e., to lock or latch the device). The magnetic field is configured to be adjustable in that it can be spatially translated away (or electrically deactivated) or translated toward (or electrically activated) the mechanism to respectively release and lock the rotating member in position. The electric field can be provided by positioning two electrodes opposing the cavity with ER material therein and electrically activating same.
More particularly, a first aspect of the invention is a portable communication device with a latching mechanism. The portable communication device includes a housing having an upper surface and a rotating member pivotably attached to the housing and a latching mechanism. The rotating member has a first closed position and a second open position. The latching mechanism is operably associated with the rotating member and is configured with a cavity. A quantity of rheological material is disposed in the cavity. (As is known to those of skill in the art, the rheological material acts as a free flowing fluid in the absence of a magnetic or electric field and acts substantially as a solid in the presence of a magnetic or electric field). The latching mechanism also includes a field source operably associated with the rheological material. The rotating member is inhibited from rotation in response to a field generated proximate to the rheological material in the cavity. The rotating member is free to rotate in the absence of a field introduced proximate to the rheological material in the cavity. In a preferred embodiment, in response to application of a magnetic field proximate to the cavity, the latching mechanism precludes rotation of the rotating member from both the first and second positions.
A second aspect of the present invention is a portable communication device with a latching mechanism. The device comprises a primary housing and a translating antenna having a stowed position and an extended position. The portable communication device also includes an antenna receptacle positioned in the housing. The receptacle defines a fluid chamber and is sized and configured to receive a major portion of the length of the antenna therein when the antenna is in a stowed position. The receptacle includes an overflow channel in fluid communication with the fluid chamber. The device also includes a quantity of rheological fluid disposed in the receptacle and a field generating means which is configured to generate a field proximate to the rheological fluid. The antenna is latched in the stowed position in response to a field generated proximate to the rheological fluid in the receptacle. Preferably, the device also includes an externally accessible latch release attached to the field generating means for controlling the introduction and removal of the field to the rheological material. Preferably, the field is a magnetic field and the rheological material is a magneto-rheological material.
Another aspect of the present invention is a latching mechanism for a translatable member. The translatable member is configured to linearly translate between retracted and extended positions. The latching mechanism includes a translatable member receptacle. The receptacle defines a fluid chamber and is sized and configured to receive a major portion of the length of the translatable member therein when the translatable member is in a retracted position. The receptacle includes a flow channel (such as an elbow) in fluid communication with the fluid chamber. As for the embodiments described above, a quantity of rheological fluid is disposed in the receptacle. The latching mechanism also includes an electric or magnetic field generating means operably associated with the electro or magneto-rheological fluid. The field generating means is configured to generate a removable field proximate to the rheological fluid such that the translatable member is latched in the retracted position in response to the electric or magnetic field generated proximate to the rheological fluid in the receptacle. Preferably, the translatable member has first and second opposing ends, and when the translatable member is in the retracted position, the channel is sized and configured to direct a quantity of the rheological fluid from below the translatable member second end to above the translatable second end.
Yet another aspect of the invention is an antenna latching mechanism for a linearly translatable antenna which is translatable between a retracted position and an extended position. The mechanism includes an antenna configured to linearly translate between retracted and extended positions and an antenna receptacle. The receptacle defines a fluid chamber and is sized and configured to receive a major portion of the length of the antenna therein when the antenna is in a retracted position. The mechanism also includes a damper having an external surface in fluid communication with the antenna receptacle. The damper has a biased first position corresponding to the substantial absence of external forces acting thereon. The damper travels inward away from the biased first position in response to forces introduced onto its external surface upon retraction of the antenna into the antenna receptacle. The mechanism also includes a quantity of rheological fluid disposed in the receptacle. The device also includes a magnetic or electric field generating means operably associated with the rheological fluid which is configured to provide a controllable field proximate to the rheological fluid. The antenna is latched in the retracted position in response to an electric or magnetic field generated proximate to the (electro or magneto) rheological fluid in the receptacle. Preferably, the antenna latching mechanism is configured with one or more of automatic deployment of the antenna toward the extended position, an externally accessible release, and an automatic magnet position reset means.
It is another aspect of the present invention to provide a deployment and latching mechanism for an antenna which uses an indirect driving means. Preferably, the mechanism includes a first rotatable gear with circumferentially extending gear teeth thereon and a longitudinally retractable and extendable antenna positioned proximate to the first rotatable gear. The antenna includes a surface which is configured to matably receive the gear teeth. The mechanism also includes a latching mechanism operably associated with the rotatable gear. The latching mechanism has a cavity and a quantity of rheological material disposed in the cavity. The device also includes one or more of a magnetic or electric field source operably associated with the rheological material. As before, the rotatable gear is inhibited from rotating in response to the magnetic field or electric field generated proximate to the rheological material in the cavity, and the rotatable gear is free to rotate in the absence of the field introduced proximate to the rheological material in the cavity. In one embodiment, the mechanism further comprises a second rotatable gear operably associated with the first rotatable gear and latching mechanism. In another embodiment, the mechanism further comprises a rotational spring having opposing first and second end portions. The first end portion is affixed to the gear, and the second end is fixed to a substantially stationary member operably associated with the latch mechanism such that the spring first end rotates corresponding to the rotation of the gear to thereby produce variable spring forces. In this embodiment, the antenna is preferably translated toward the extended position by the force attributed to the spring load exerted onto the gear by the wound rotational spring.
It is yet another aspect of the invention to provide a locking mechanism which has a user depressed release which locks a cover or flip to the housing and automatically resets the release when the cover is closed. Preferably, this locking mechanism is used to also position the magnet in the desired location for the MR latching devices described above.
In each of the embodiments, the magnetic field source or magnetic field generating means can be either one or more permanent magnets and/or an electro-magnet or electric field provided by a coil or electrodes positioned proximate to the rheological material. Further, the magneto-rheological material can alternatively be an electro-rheological material.
The present invention also includes latching mechanisms corresponding to one or more of the devices described above.
The present invention is advantageous because the separate functions of a damper and a latch can be advantageously combined into an integrated latching mechanism which can be configured to fit into a relatively small volume. The viscous material in the rotating mechanism provides a suitable damper when the flip or antenna member is deployed and then can be used to latch the member during non-deployment periods. The latching mechanism is also robust and relatively non-complex and does not require mounting or operational space on the flip itself. Further, the latching mechanism can be conveniently positioned at the top of the radiotelephone and performs the latching function in a manner which reduces the amount of force exerted on the mechanical components or needed by the user. In addition, the latching mechanism can lock the rotating member in both the open and closed positions (against the body of the radiotelephone and in the extended operational position). The rotational latch also includes an externally accessible magnet release and can also include a release or magnet reset which operates upon translation of the flip toward the main housing and automatically resets when the cover returns to a stow position.
The antenna latching mechanisms can provide latching at various antenna extensions such as in both the retracted and extended positions. In one embodiment, the latching mechanism of the present invention is configured to bias the antenna toward the operational position (i.e., facilitate automatic deployment of the antenna toward the extended position) and can also conveniently include an automatic release reset which is activated upon retraction of the antenna.